From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx126.postini.com [74.125.245.126]) by kanga.kvack.org (Postfix) with SMTP id 194CB6B002B for ; Mon, 15 Oct 2012 22:35:15 -0400 (EDT) Received: by mail-oa0-f41.google.com with SMTP id k14so7018225oag.14 for ; Mon, 15 Oct 2012 19:35:14 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20121008150949.GA15130@redhat.com> References: <20121008150949.GA15130@redhat.com> From: KOSAKI Motohiro Date: Mon, 15 Oct 2012 22:34:53 -0400 Message-ID: Subject: Re: mpol_to_str revisited. Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Dave Jones , Linux Kernel , bhutchings@solarflare.com, linux-mm@kvack.org, Linus Torvalds , Andrew Morton On Mon, Oct 8, 2012 at 11:09 AM, Dave Jones wrote: > Last month I sent in 80de7c3138ee9fd86a98696fd2cf7ad89b995d0a to remove > a user triggerable BUG in mempolicy. > > Ben Hutchings pointed out to me that my change introduced a potential leak > of stack contents to userspace, because none of the callers check the return value. > > This patch adds the missing return checking, and also clears the buffer beforehand. I don't think 80de7c3138ee9fd86a98696fd2cf7ad89b995d0a is right fix. we should close a race (or kill remain ref count leak) if we still have. Because of, this patch makes unstable /proc output and might lead to userland confusing. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org